Micro heat flux sensor array

ABSTRACT

Provided is a micro heat flux sensor array having reduced heat resistance. A micro heat flux sensor array may include a substrate, a plurality of first sensors formed on a first side of the substrate, and a plurality of second sensors formed on a second side of the substrate. Each of the plurality of first and second sensors may include a first wiring pattern layer of a first conductive material, a second wiring pattern layer of a second conductive material contacting the first wiring pattern layer, and an insulating layer in contact with the first and second wiring patterns.

PRIORITY CLAIM

This application is a Divisional of U.S. application Ser. No. 11/700,905filed Feb. 1, 2007, which claims the benefit of the Korean PatentApplication No. 10-2006-0010716 filed on Feb. 3, 2006, both of which areincorporated by reference in their entirety.

BACKGROUND

1. Field of the Example Embodiments

Example embodiments may relate to a micro heat flux sensor array. Moreparticularly, example embodiments may relate to a micro heat flux sensorarray capable of measuring heat flux in all directions.

2. Description of the Related Art

Due to the ever increasing performance level of semiconductor chips, theoperating power of semiconductor chips continues to increase. In thecase of microprocessors, memories, and micro-electro-devices(semiconductor chips), heat generated during operation of asemiconductor chip must be effectively radiated to reduce/prevent thedeterioration of the semiconductor chip. In order to effectively radiateheat from a semiconductor package containing a semiconductor chip,temperatures of each component of the semiconductor chip should bemeasured.

Thus, due to an increasing need to accurately measure physicalquantities that indicate heat transfer in the semiconductor chip,various heat flux sensors are being developed.

However, conventional heat flux sensors on the surface of asemiconductor chip may act as heat resistances; therefore, it may bedifficult to accurately measure the heat flux. Also, it may be difficultto accurately determine the heat transfer route, because conventionalheat flux sensors may measure the heat flux after the heat transferroute has been altered by the heat flux sensor.

SUMMARY

Example embodiments may provide a micro heat flux sensor array having areduced heat resistance.

In an example embodiment, a micro heat flux sensor array may include asubstrate, a plurality of first sensors formed on a first side of thesubstrate, and a plurality of second sensors formed on a second side ofthe substrate. The plurality of first and second sensors each mayinclude a first wiring pattern layer of a first conductive material, asecond wiring pattern layer of a second conductive material contactingthe first wiring pattern layer, and an insulating layer, interposedbetween the first and second wiring pattern layers, having via holestherein through which the first and second wiring pattern layers makecontact, respectively.

In another example embodiment, a micro heat flux sensor array mayinclude a substrate, a plurality of first sensors formed on a first sideof the substrate, and a plurality of second sensors formed on a secondside of the substrate. Each of the plurality of first and second sensorsmay include a first wiring pattern layer of a first conductive material,a second wiring pattern layer of a second conductive material contactingthe first wiring pattern layer, an insulating layer, interposed betweenthe first and second wiring pattern layers, having via holes thereinthrough which the first and second wire pattern layers make contact,respectively, and a plurality of grooves formed at desired intervals onthe insulating layer.

In another example embodiment, a micro heat flux sensor array mayinclude a substrate, a plurality of first sensors formed on a first sideof the substrate, and a plurality of second sensors formed on a secondside of the substrate. Each of the plurality of first and second sensorsmay include a first wiring pattern layer of a first conductive material,a second wiring pattern layer of a second conductive material contactingthe first wiring pattern layer, an embossed insulating layer having aplurality of protrusions at desired intervals and in contact with thefirst and second wiring patterns, and a plurality of grooves formedbetween adjacent protrusions on the insulating layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a disassembled perspective view illustrating a micro heat fluxsensor array according to an example embodiment;

FIG. 2 is an assembled perspective view illustrating the micro' heatflux sensor array of FIG. 1;

FIG. 3 is a sectional view taken along a line III-III′ of FIG. 2;

FIGS. 4A through 4E are sectional view sequentially illustrating amethod of fabricating a micro heat flux sensor array according to anexample embodiment;

FIG. 5 is a perspective view illustrating a micro heat flux sensor arrayaccording to another example embodiment;

FIG. 6 is a disassembled perspective view illustrating a micro heat fluxsensor array according to another example embodiment;

FIG. 7 is an assembled perspective view illustrating the micro heat fluxsensor array of FIG. 6;

FIG. 8 is a sectional view taken along a line VIII-VIII′ of FIG. 7;

FIGS. 9A through 9C are sectional view sequentially illustrating amethod of fabricating a micro heat flux sensor array according toanother example embodiment.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Features of example embodiments may be understood more readily byreference to the following detailed description thereof and theaccompanying drawings. Example embodiments may, however, be embodied inmany different forms and should not be construed as being limited to thedescription set forth herein. Rather, example embodiments may beprovided so that this disclosure will be thorough and will convey theconcept of the example embodiments to those skilled in the art. Likereference numerals refer to like elements throughout the specification.

It will be understood that when an element or layer is referred to asbeing “on”, “connected to” or “coupled to” another element or layer, itmay be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to”or “directly coupled to” another element or layer, there may be nointervening elements or layers present. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms may beonly used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section discussed below could be termed asecond element, component, region, layer or section without departingfrom the teachings of the present invention.

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms may be intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the example term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a”, “an” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Example embodiments may be described herein with reference tocross-section illustrations that may be schematic illustrations ofidealized embodiments (and intermediate structures). As such, variationsfrom the shapes of the illustrations as a result, for example, ofmanufacturing techniques and/or tolerances, are to be expected. Thus,the example embodiments should not be construed as limited to theparticular shapes of regions illustrated herein but are to includedeviations in shapes that result, for example, from manufacturing. Forexample, an implanted region illustrated as a rectangle will, typically,have rounded or curved features and/or a gradient of implantconcentration at its edges rather than a binary change from implanted tonon-implanted region. Likewise, a buried region formed by implantationmay result in some implantation in the region between the buried regionand the surface through which the implantation takes place. Thus, theregions illustrated in the drawings are schematic in nature and theirshapes are not intended to illustrate the actual shape of a region of adevice and are not intended to limit the example embodiments.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art. It will be further understood that terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and will not be interpreted in anidealized or overly formal sense unless expressly so defined herein.

Hereinafter, an example embodiment will be described with reference toFIGS. 1 through 4E.

First, a micro heat flux sensor array according to an example embodimentwill be described with reference to FIGS. 1 through 3. FIG. 1 is adisassembled perspective view illustrating a micro heat flux sensorarray according to an example embodiment; FIG. 2 is an assembledperspective view illustrating the micro heat flux sensor array of FIG.1; and FIG. 3 is a sectional view taken along a line III-III′ of FIG. 3.

Referring to FIGS. 1 through 3, a micro heat flux sensor array 100 mayinclude a substrate 10, an upper sensor having a first wiring patternlayer 20, an insulating layer 30, and a second wiring pattern layer 40,which may be sequentially stacked on a first side of the substrate 10,and a lower sensor having a first wiring pattern layer 20′, aninsulating layer 30′, and a second wiring pattern layer 40′, which maybe symmetrical to the upper sensor and sequentially stacked on a secondside of the substrate 10.

In order to apply the micro heat flux sensor array 100 to anyarea/device to be measured, a flexible film may be used as the substrate10. For example, polyimide (PI) may be used as the substrate 10. Also,in order to reduce the heat resistance of the micro heat flux sensorarray 100, the heat conductivity of the micro heat flux sensor array 100may be increased by further providing conductive metal balls (not shown)on the substrate 10.

The first wiring pattern layer 20 of a first conductive material may beformed on the first side of the substrate 10. The first wiring patternlayer 20 may include a first measuring pattern 22, which may be providedat each temperature measurement site, and a first routing wire 24connecting the respective first measuring pattern 22 to an external heatflux measuring apparatus 200. The surface of the first wiring patternlayer 20 may be plated with a plating layer in order to prevent/reducecorrosion and to increase strength. For example, tin (Sn) may be used asthe plating layer.

The first wiring pattern layer 20 and the first measuring pattern 22 maybe formed on the insulating layer 30. Solder-resist (SR) may be used asthe insulating layer 30.

The second wiring pattern layer 40 of a second conductive material maybe disposed on the insulating layer 30. The second wiring pattern layer40 may include a second measuring pattern 42, which may provided atlocations corresponding to the first measuring pattern 22, a secondrouting wire 44 connecting the respective second measuring pattern 42 tothe external heat flux measuring apparatus 200, and a connection pattern46 which may protrude from the respective second measuring pattern 42through via holes 32 to contact the first measuring pattern 22. Thesurface of the second wiring pattern layer 40 may be plated with aplating layer in order to prevent/reduce corrosion and to increasestrength. For example, tin (Sn) may be used as the plating layer.

The first conductive material of the first wiring pattern layer 20 andthe second conductive material of the second wiring pattern layer 40 maybe of different materials with respect to each other, or may be of thesame material. If the first metal pattern layer 20 and the second metalpattern layer 40 are of different materials, the first metal patternlayer 20 and the second metal pattern layer 40 may form a thermocouple,and a potential difference between the first wiring pattern layer 20 andthe second wiring pattern layer 40 may be measured by the heat fluxmeasuring apparatus 200 to calculate heat flux. The heat fluxcalculating method will be explained in detail later.

To facilitate the connection of the first routing wire 24 and the secondrouting wire 44 to the heat flux measuring apparatus 200, the firstrouting wire 24 and the second routing wire 44 may be routed in variousdirections.

As described above, because the lower sensor may include the firstwiring pattern layer 20′, the insulating layer 30′, and the secondwiring pattern layer 40′ sequentially stacked on the substrate 10, whichmay be similarly configured as the upper sensor, an explanation thereofwill be omitted. In order to efficiently measure the heat flux in avertical direction, bond portions of the first wiring pattern layers 20,20′ and the second wiring pattern layers 40, 40′, which are respectivelydisposed on both sides of the substrate 10, may be located along thesame perpendicular line. In other words, the first measuring patterns22, 22′ and the second measuring patterns 42, 42′ may be preferablypositioned along the same perpendicular line.

Hereinafter, operation of the micro heat flux sensor array according toan example embodiment will be described with reference to FIGS. 2 and 3.

In the example embodiment, the first wiring pattern layers 20, 20′ andthe second wiring pattern layers 40, 40′ may be of different materials.

In general, in a closed circuit having two regions on either side of abond portion with two kinds of electrically conductive materials, apotential difference between the two regions may be created bymaintaining the two regions at different temperatures. The correlationbetween temperature and electromotive force varies according to the kindof conductive material, and the correlation due to the Seebeck effectbetween temperature and electromotive force is known. Therefore, thetemperature may be calculated by measuring the potential difference. Asensor which measures temperature using two kinds of conductivematerials that are in contact with each other is called a thermocouplesensor.

As illustrated in FIGS. 2 and 3, the micro heat flux sensor array 100may include an upper thermocouple sensor having the first wiring patternlayer 20 and the second wiring pattern layer 40 on the substrate 10, anda lower thermocouple sensor having the first wiring pattern layer 20′and the second wiring pattern layer 40′ below the substrate 10.

Each of the upper and the lower thermocouple sensors may be constructedsuch that the first measuring patterns 22, 22′ of the first wiringpattern layer 20, 20′ are connected to the second measuring pattern 42,42′ of the second measuring pattern layer 40, 40′ by the connectionpatterns 46, 46′.

Hereinafter, a method of measuring the heat flux of an area/device whoseheat flux is to be measured in a state in which the second wiringpattern layer 40′ of the lower thermocouple sensor is connected to thearea/device will be described. Referring to FIG. 3, heat generated bythe area/device may migrate in both horizontal and vertical directionsthrough the micro heat flux sensor array 100. For example, if thetemperature of thermocouple sensor A and the temperature of thermocouplesensor B are measured, the heat flux which may be generated by thearea/device and migrates in the horizontal direction may be inferred.Also, if the temperature of thermocouple sensor A and thermocouplesensor C are measured, the heat flux which may be generated by thearea/device and migrates in the vertical direction may also be inferred.

As described above, according to the micro heat flux sensor array 100 ofthe example embodiment, a plurality of heat flux thermocouple sensorsmay be formed on the upper side and the lower side of the substrate 10to measure both the horizontal and vertical heat flux. Also, conductivemetal balls may be disposed on the substrate 10 in order to increase theheat conductivity of the micro heat flux sensor array 100 to lower theheat resistance of the micro heat flux sensor array 100.

In another example, the first wiring pattern layer 20, 20′ and thesecond wiring pattern layer 40, 40′ may be of the same material.

In general, the resistance of a conductive material may be proportionalto the temperature of the conductive material. The correlation betweentemperature and resistance varies according to the type of theconductive material, wherein the temperature may be calculated bymeasuring the resistance. A sensor which measures temperature based onthe resistance of the conductive materials is called a ResistanceTemperature Detector (RTD).

As shown in FIGS. 2 and 3, the micro heat flux sensor array 100 mayinclude an upper RTD having the first wiring pattern layer 20 and thesecond wiring pattern layer 40 on the substrate 10, and a lower RTDhaving the first wiring pattern layer 20′ and the second wiring patternlayer 40′ below the substrate 10.

Components of each of the upper and the lower RTD may be connected bythe connection patterns 46, 46′, which may connect the first measuringpatterns 22, 22′ to the second measuring patterns 42, 42′, respectively.

A method of measuring the heat flux of an area/device whose heat flux isto be measured in a state in which the second wiring pattern layer 40′of the lower RTD is connected to the area/device will be described.Referring to FIG. 3, heat which may be generated by the area/device maymigrate in both horizontal and vertical directions through the microheat flux sensor array 100. For example, if the temperature of RTD A andthe temperature of RTD B are measured, the heat flux which may begenerated by the area/device and migratesin the horizontal direction maybe inferred. Also, if the temperature of RTD A and the temperature ofRTD C are measured, the heat flux which may be generated by thearea/device and migrates in the vertical direction may also be inferred.

As described above, according to the micro heat flux sensor array 100 ofthe example embodiment, a plurality of RTDs may be disposed on the upperside and the lower side of the substrate 10 to measure both thehorizontal and vertical heat flux. Also, conductive metal balls may bedisposed on the substrate 10 in order to increase the heat conductivityof the micro heat flux sensor array 100 to lower the heat resistance ofthe micro heat flux sensor array 100.

Hereinafter, a method of fabricating a micro heat flux sensor arrayaccording to an example embodiment will be described with reference toFIG. 3 and FIGS. 4A through 4E. FIGS. 4A through 4E are sectional viewssequentially illustrating a method of fabricating a micro heat fluxsensor array according to an example embodiment.

As shown in FIG. 4A, a first conductive layer 120 may be formed on apolyimide substrate 10. The first conductive layer 120 may be formed onthe substrate 10 by an electroplating method after forming a seed layerby a sputtering method.

To control the thickness of the first conductive layer 120 or remove anoxidation layer on the first conductive layer 120, a soft etchingprocess may be performed.

The first conductive layer 120 may be patterned to form a first wiringpattern layer 20 as illustrated in FIG. 4B. In addition, anelectroplating process to electroplate the surface of the first wiringpattern layer 20 with tin (Sn) or another metal may be performed (notshown).

Referring to FIG. 4C, an insulating layer 30 including a via hole 32 maybe formed on the first wiring pattern layer 20. The insulating layer 30may be formed by a screen printing method.

As illustrated in FIG. 4D, a second conductive layer 140 may be formedon the insulating layer 30. The second conductive layer 140 may beformed on the substrate 10 by an electroplating method after forming aseed layer by a sputtering method.

The second conductive layer 140 may be patterned to form a second wiringpattern layer 40 as illustrated in FIG. 4E. In addition, anelectroplating process to electroplate the surface of the second wiringpattern layer 40 with tin (Sn) or another metal may be performed (notshown).

As described above, after the upper sensor is formed a first side of thesubstrate 10, the same process may be performed on a second side of thesubstrate 10. For example, as illustrated in FIG. 3, a first wiringpattern layer 20′, an insulating layer 30′, and a second wiring patternlayer 40′ may be formed on the second side of the substrate 10 tocomplete the manufacturing of the lower sensor.

Hereinafter, another example embodiment will be described with referenceto FIG. 5. FIG. 5 is a perspective view illustrating a micro heat fluxsensor array according to another example embodiment. The description ofelements having the same function as elements in the drawings of thefirst example embodiment (FIGS. 4A-4E) are represented with the samereference numerals, and therefore, explanations thereof will be omitted.As illustrated in FIG. 5, a micro heat flux sensor array 500 accordingto the example embodiment may have the same structure as the micro heatflux sensor array 100 of the first example embodiment. However, aplurality of grooves 532, 532′ may be formed on insulating layers 530,530′ at desired intervals, as illustrated in FIG. 5. The grooves 532,532′, for example, may be formed at bond portions between the adjacentfirst wiring pattern layer 20, 20′.

An accurate measurement may be performed by forming the groove 532, 532′on the insulating layer 530, 530′. A case in which the second wiringpattern layer 40′ located under the substrate 10 contacts an area/devicewhose heat flux is to be measured will be described. As illustrated inFIG. 5, temperature of region A and temperature of region B may bemeasured to ascertain the heat flux which may be generated by thearea/device and migrates in a horizontal direction. Also, thetemperature of region A and temperature of region C may be measured toascertain the heat flux which may be generated by the area/device andmigratesin a vertical direction.

Inconsistent and inaccurate measurements of the horizontal heat fluxbetween region A and region B may be reduced and/or avoided with exampleembodiments, because the area/device directly contacts the second wiringpattern layer 40′ at region A and region B. However, in the case of thevertical heat flux, the heat released from region A may not migratevertically, but radiate like spokes on a wheel, so a vertical heat fluxdifference may occur. In other words, the migrating heat from region Anot only reaches region C but may also reach region D. Therefore, themeasured temperature of region C may be lowered than the truetemperature.

As described above, the grooves 532, 532′ may be formed on theinsulating layers 530, 530′ in order to reduce measurement error of thehorizontal heat flux. Because the grooves 532, 532′ reduce and/orprevent heat from migrating in a horizontal direction, the heat flux inthe vertical direction may be accurately measured.

Hereinafter, another example embodiment will be described with referenceto FIGS. 6 through 9C.

First, a micro heat flux sensor array according to the exampleembodiment will be described with reference to FIGS. 6 through 8. FIG. 6is a disassembled perspective view illustrating a micro heat fluxsensor. FIG. 7 is an assembled perspective view illustrating the microheat flux sensor array of FIG. 6, and FIG. 8 is a sectional view takenalong a line VIII-VIII′ of the micro heat flux sensor array of FIG. 7.

Referring to FIGS. 6 through 8, a micro heat flux sensor array 600 mayinclude a substrate 610, an upper sensor having an insulating layer 620,a first wiring pattern layer 630, and a second wiring pattern layer 640,which may be sequentially stacked a first side of the substrate 610, anda lower sensor having an insulating layer 620′, a first wiring patternlayer 630′, and a second wiring pattern layer 640′, which may besymmetrical to the upper sensor, and sequentially stacked on a secondside of the substrate 610.

In order to arrange the micro heat flux sensor array 600 to the shape ofany area/device to be measured, a flexible film may be used as thesubstrate 610. For example, polyimide (PI) may be used as the substrate610. In order to reduce the heat resistance of the micro heat fluxsensor array 600, the heat conductivity of the micro heat flux sensorarray 600 may be raised by adding conductive metal balls (not shown) tothe substrate 610.

The insulating layer 620 formed on one side of the substrate 610 may beembossed. In other words, the insulating layer 620 may include grooves622 at desired intervals. The insulating layer 620 may be formed ofsolder resist (SR).

The first wiring pattern layer 630 of a first conductive material may beformed on the insulating layer 620. The first wiring pattern layer 630may include a first measuring pattern 632, which may be formed at eachtemperature measurement site, and first routing wires 634 connecting thefirst measuring pattern 632 to an external heat flux measuring apparatus200. The surface of the first wiring pattern layer 630 may be platedwith a plating layer in order to prevent/reduce corrosion and increasestrength. For example, tin (Sn) may be used as the plating layer.

The second wiring pattern layer 640, which may include a secondconductive material, may partially overlap the first wiring patternlayer 630, and may be formed on the insulating layer 620. The secondwiring pattern layer 640 may include a second measuring pattern 642which overlap and contact the first measuring patterns 632, and a secondrouting wire 644 connecting the second measuring pattern 642 to anexternal heat flux measuring apparatus 200. The surface of the secondwiring pattern layer 640 may be plated with a plating layer in order toprevent/reduce corrosion and to increase strength. For example, tin (Sn)may be used as the plating layer.

The first measuring pattern 632 and the second measuring pattern 642,which contact an area/device where heat flux may be measured; may beformed on a protrusion of the insulating layer 620. In other words, theinsulating later 620 may include step areas (embossed) where the firstmeasuring pattern 632 and the second measuring pattern 642 may beprovided. Also, the first routing wire 634, which may be connected withthe first measuring pattern 632, and the second routing wire 644, whichmay be connected with the second measuring pattern 642, may be formed onthe groove 622 in order to prevent/reduce disconnection caused bycontact with the area/device to be measured.

The first conductive material of the first wiring pattern layer 630 andthe second conductive material of the second wiring pattern layer 640may be of different materials or may be the same material. As describedin the first example embodiment, when the first wiring pattern layer 630and the second wiring pattern layer 640 may be of different materials,the first wiring pattern layer 630 and the second wiring pattern layer640 may form a thermocouple, and a potential difference between thefirst wiring pattern layer 630 and the second wiring pattern layer 640may be measured by the heat flux measuring apparatus 200 to calculateheat flux. Also, when the first wiring pattern layer 630 and the secondwiring pattern layer 640 are of the same material, a resistance betweenthe first wiring pattern layer 630 and the second wiring pattern layer640 may be measured by the heat flux measuring apparatus 200, and themeasured resistance may be used to calculate the heat flux.

In order to facilitate connection of the first routing wire 634 and thesecond routing wire 644 to the heat flux measuring apparatus 200, thefirst routing wire 634 and the second routing wire 644 may be routed invarious directions.

As described above, the lower sensor may include the insulating layer620′, the first wiring pattern layer 630′, and the second wiring patternlayer 640′ sequentially stacked on a second side of the substrate 610,including grooves 622′, substantially in the same manner as the uppersensor, accordingly an explanation thereof will not be provided. Inorder to efficiently measure the heat flux in a vertical direction, bondportions of the first wiring pattern layer 630, 630′ and the secondwiring pattern layer 640, 640′ arranged on each side of the substrate610 may be located along the same perpendicular line.

Operation of the micro heat flux sensor array according to the exampleembodiment is similar to the second example embodiment. In other words,the example embodiment not only accurately measures the horizontal heatflux, but may also reduce the vertical heat flux error by the grooves622, 622′ formed on the insulating layer 620, 620′.

Hereinafter, a method of fabricating a micro heat flux sensor arrayaccording to the example embodiment will be described with reference toFIG. 8, and FIGS. 9A-9C. FIGS. 9A through 9C are sectional viewssequentially illustrating a method of fabricating a micro heat fluxsensor array.

As shown in FIG. 9A, an insulating layer 620 may be formed on apolyimide substrate 610. The insulating layer 620 may include aplurality of grooves 622 spaced apart from one another at desiredintervals. The insulating layer 620 may be formed by a screen printingmethod.

Next, referring to FIG. 9B, a first conductive layer (not shown) may beformed on the insulating layer 620, and the first conductive layer maybe patterned to form a first wiring pattern layer 630. The firstconductive layer may be formed by an electroplating method after a seedlayer is formed on the insulating layer 620 by a sputtering method. Inaddition, an electroplating process to electroplate a surface of thefirst wiring pattern layer 640 with tin (Sn) may be performed (notshown).

Referring to FIG. 9C, a second conductive material layer (not shown) maybe formed on the first wiring pattern layer 630, and the secondconductive material layer may be patterned to form the second wiringpattern layer 640, which may overlap a desired portion of the firstwiring pattern layer 630. The second conductive layer may be formed byan electroplating method after a seed layer is formed on the substrate610 by the sputtering method. In addition, an electroplating process toelectroplate a surface of the first wiring pattern layer 640 with tin(Sn) may be performed.

As described above, after the upper sensor is formed a first side of thesubstrate 610, the same process may be performed again a second side ofthe substrate 610. Therefore, as illustrated in FIG. 8, an insulatinglayer 620′, a first wiring pattern layer 630′, and a second wiringpattern layer 640′ may be formed on the second side of the substrate 610to complete the lower sensor.

While example embodiments have been illustrated and described, it willbe apparent to those skilled in the art that all variations andequivalents which fall within the range of the claims attached theretoare intended to be embraced therein. Therefore, it should be understoodthat the above example embodiments are not limitative, but illustrativein all aspects.

As described above, in the structures and methods of fabricating microheat flux sensor array according to example embodiments may reduce heatresistance of the micro heat flux sensor and accurately measurehorizontal heat flux as well as vertical heat flux.

1. A micro heat flux sensor array, comprising: a substrate; a pluralityof first sensors formed on a first side of the substrate; and aplurality of second sensors formed on a second side of the substrate,wherein each of the plurality of first and second sensors include, afirst wiring pattern layer of a first conductive material, a secondwiring pattern layer of a second conductive material contacting thefirst wiring pattern layer, an embossed insulating layer having aplurality of protrusions at desired intervals and in contact with thefirst and second wiring pattern layers, and a plurality of groovesformed between adjacent protrusions on the insulating layer.
 2. Themicro heat flux sensor array of claim 1, wherein the first wiringpattern layer and the second wiring pattern layer contact each other onthe respective plurality of protrusion.
 3. The micro heat flux sensorarray of claim 1, wherein the first wiring pattern layer includes aplurality of first measuring patterns disposed on respective temperaturemeasuring regions, and a plurality of first routing wires configured toconnect the plurality of first measuring pattern to an external heatflux measuring apparatus.
 4. The micro heat flux sensor array of claim3, wherein the second wiring pattern layer includes a plurality ofsecond measuring patterns disposed on locations corresponding to theplurality of first measuring pattern, and a plurality of second routingwires configured to connect the respective plurality of second measuringpatterns to the external heat flux measuring apparatus.
 5. The microheat flux sensor array of claim 1, wherein the first wiring patternlayer and the second wiring pattern layer are of different materials. 6.The micro heat flux sensor array of claim 1, wherein the first wiringpattern layer and the second wiring pattern layer are of the samematerial.
 7. The micro heat flux sensor array of claim 1, wherein thesubstrate includes a flexible film.
 8. The micro heat flux sensor arrayof claim 1, wherein the substrate includes conductive metal balls.